Apparatus for cleaning hot blast stove flues



F. WEIR April 24, 1945.

APPARATUS FOR CLEANING HOT BLAST STOVE FLUES 2 Sheets-Sheet 1 Filed May 8, 1943 T mm a WM w k m F F. WEIR April 24, 1945.

APPARATUS FOR CLEANING HOT BLAST STOVE FLUES INVENTOR- J y m v HxZHZZZZZ VZ/Z,2 W, I M

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Patented Apr. 24, 1945 APPARATUS FOR CLEANING HOT BLAST STOVE FLUES Frank Weir, Duquesne, Pa., assignor to Camegie- Illinois Steel Corporatio Jersey n, a corporation of New Application May 8, 1943, Serial No. 486,224

1 3 Claims.

This invention relates to apparatus for cleaning hot blast stove flues. In the operation of blast furnaces air is introduced at the lower part of v the furnace. In order to reduce the amount of fuel required, the air is heated in a number of hot blast stoves located near each furnace. The stoves are cylindrical in form, constructed of heavy steel plate to withstand the internal air pressure and are lined with fire brick. Within the stove is a combustion chamber and numerous small vertical passages known as checker flues. The heated gases from the combustion chamber pass through the checker flues giving up a portion of their sensible heat to the flue walls. After the checkers have been heated, a blast of air is passed through the checker flues absorbing the heat from the checkers. The stoves burn blast furnace gas which contains a lot of dust as it comes from the furnace. The dust is removed as thoroughly as possible before burning in the stove, but in spite of this, the checker flues tend to become blocked by dust settling on the flue walls. When small flues and small stoves are used, the flues may become completely blocked. Broken brick from the flues also increase the danger of having the flues entirely blocked. In order to maintain the effectiveness of the stoves, the checker flues must be periodically cleaned. The dust, besides plugging the checker flues, acts as a heat insulator which retards the flow of heat to and from the brick walls of the stove.

At present the common practice of cleaning flues is to allow the stove to cool when out of service, after which the workers enter the stoves above the checkers and by means of sledges and sections of pipes having pointed ends force an opening through the obstructing dust to the checker flues. This is followed by using a blast of compressed air on the walls to clean them. In some instances air or steam nozzles are built into the stove and air or steam is periodically applied to clean the flues before they are badly plugged. To remove bricks from the flues a heavy dolly bar attached to a steel cable is dropped on the brick. The dust from the checkers falls to the bottom of the stove and is taken out through the doors in the sides of the stove.

Another object of the invention is to provide an improved self-propelled flue cleaner.

A further object is to provide a flue cleaner which will remove obstructions in the flue as well as clean the walls.

These and other objects will be more apparent after referring to the following description and attached drawings in which:

Fig. 1 is an elevation of the flue cleaner of the present invention;

Fig. 2 is an end view of the same;

F1Fig. 3 is a view taken on section III-III of Fig. 4 is a vertical section showing the flue cleaner in operation; and

Fig. 5 is a sectional view taken on line V-V of Fig 4.

Referring more particularly to the drawings the flue cleaner is made from a piece of A" pipe 2 about thirty inches long. The front end of the pipe 2 is welded shut and a A" diameter hole 4 is drilled therethrough on the center line of the pipe. A short distance from the front of the pipe four 1%" diameter holes 6 are drilled radially in the pipe wall, the holes being equally spaced around the circumference of the pipe. A second group of holes 6 are drilled in the pipe several inches from the first group of holes. These holes are spaced about the pipe in staggered relation with respect to the first group of holes.

Eight pieces of pipe 8 about four inches long are cut or ground lengthwise on an angle so that starting from the small end of the section of pipe the width of the pipes gradually increases to the opposite end. One of the pipe section 8 is welded to the walls of the pipe 2 over each of the radial holes 6 with the small ends of the pipe 8 toward nozzle 4. The small end of each pipe section is welded shut. The flared segments of pipe guide the air streams outwardly against the flue walls as best shown in Fig. 4. The rear end of the pipe 2 is inserted in the end of an air hose l0 and held in place by a wire clamp l2. It will be understood that other sizes and lengths of pipe may be used, the sizes and lengths of pipe given being by way of illustration. In place of air, other fluids could be used to clean the flues.

Fig. 4 shows the flue cleaner cleaning one of the flues M of a hot blast stove. The air hose I0 is attached to a compressed air pipe I6 and the supply of air to the cleaner is controlled by means of the valve l8.

The method of cleaning the flue is as follows: The workmen enter the dome of the stove through the door on the top with about one hundred feet of air hose attached to the flue cleaner. The flue cleaner attached to the air hose is started down in the checker flue l4 and the air valve l8 opened. The air stream from the orifice 4 blows the dust from the flue walls and the flue cleaner is propelled downwardly by means of the air streams from the eight holes 6 going rearwardly through pipes 8. When the flue cleaner arrives at the bottom of the checker flue, the workmen begintopullitupwardlybymeansofthehoseil.

The air valve ll remains open until the flue cleaner is near the top of thecheckers, the eight streams of airfromthepipealthoroughly cleaningthedust fromthefluewalls. Oneroundtrlp is ordinarily suflleient to eleanthe flues. The two rings of holes I produce a Jet action which tends to keep the flue cleaner in the center of the flue, thus giving a more eiflcient cleaning action and also preventing the upper edges of the pipe sections' 8 from catching on projections in the flues when withdrawing the cleaner. The radial arrangement of the holes enables the corners as well astheflatwallsurfacestobecleaned.

When a plugged flue is found the flue cleaner is pulledupashortdistanceandallowedtodropa number of times. If the flue is plugged only by dusttheietinthetipagitatesthedustand the flue cleaner will work its way through the plug in a few minutes. The air jets discharging rearmay be made without departing from the scope of the attached claims.

I claim:

1. A flue cleaner comprising a tube having a nozzle in the front end thereof, the walls of the tube having radial holes therein, said tube having a second group of radial holes spaced from the flrst group, a hollow covering over each of said holes, each covering being closed at the front and open at the rear, said coverings flaring outwardly toward said open end and means for applying fluid pressure to the tube.

2. A flue cleanercomprising a tube having a nozzle in the front end thereof, the walls of the tube having radial holes therein, said tube having a second group of radial holes spaced from the first group, the second group of holes being staggered with reference to said first group, a

hollow covering over each of said holes, each covering being closed at the front and open at the rear. the coverings flaring outwardly toward said open end and means for applying fluid pressure to the tube.

3. A flue cleaner comprising a tube having a nozzle in the front end thereof, the walls of the tube having radial holes therein, a hollow coverin over each of said holes, each covering being closed at the front and open at the rear, said coverings flaring outwardly toward said open end and means for applying fluid pressure to the tube.

FRANKWEIR. 

